Aspect ratio and limits

Try (with a sufficiently recent version of R)

xyplot(y~x, data=xy, aspect="iso")

Is that what you want?

Yes, that's the badger, as we say round here.

  Of course my two-point scatterplot is a simplification of the actual 
data, which consists of nine lines something like a time series, to be 
drawn in different line styles and with a key.

  Maybe this is a good time to really figure out how to do stuff with 
grid/lattice graphics...

thanks,

Barry